ZOOLOGY AND BOTANY. MICROSCOPY, ETC. 319 



has two layers, with an inner limiting layer. The sheath of the plerome 

 and the inner layer of the periblem have a common origin. 



Physiology. 

 Nutrition and Growth. 



Respiration of the Flower.* — A. Maige has investigated a large 

 number of species, including Gucumis sativiis, Hibiscus rosa-sinensis, 

 Veronica spicata, etc., with the view of ascertaining how the intensity of 

 respiration of the flower varies. The author finds that respiratory 

 intensity regularly decreases as the flower approaches maturity, but that 

 the rapidity of decrease is very variable in different species. A few 

 species, however, maintain a constant respiratory intensity, while others 

 are exceptional, in that respiration is greatest when the flower is about 

 to fade. These conclusions hold good, whether respiration is determined 

 by the amount of CO2 given off, or by an estimation of the weight of the 

 flower. In most of the species examined, the dry weight gradually 

 decreases as the flower reaches its full development, but here, again, 

 there are exceptions corresponding with those previously mentioned. 



Irritability- 

 Action of Electricity upon Germination.t — P. Lesarge has investi- 

 gated the indirect effects of electricity upon the spores of PenicilUum 

 and various seeds. In the former case germination was hindered, but 

 subsequent investigations seem to show that a similar effect is produced 

 by growing the spores in an atmosphere impregnated with ozone and 

 nitrogen peroxide ; since these substances are always present in the 

 atmosphere in the neighbourhood of an electric current, the hindrance 

 of germination is probably an indirect result of electrical influence. In 

 the case of various seeds which germinated wliile under the influence of 

 an electric current, the results appear to depend chiefly upon three 

 factors — (1) the length of time that the seeds were soaked in water, 

 (2) the action of heat induced by the current, (3) the influence of the 

 products of electrical action upon the air. 



Metallotropism of Phycomyces nitens.J — A. Henckel and A. 

 Tschernjajew cultivated plants of Phycomyces nitens with copper, iron, 

 and aluminium in close proximity. They found that iron attracted the 

 plants ; aluminium attracted them to a less extent ; copper had a 

 repellent influence. They also tested the influence of these metals 

 within glass tubes, and found that the glass did not interfere with the 

 effect. 



General. 



New Genus of Conifers from Formosa. §— Bunzo Hayata describes a 

 new Conifer, Taiwania, found at 2000 metres elevation on Mt. Morrison, 



* Rev. Gen. de Bot., xix. (1907) pp. 8-28. 

 t Comptes Rendus, cxliii. (1906) pp. G95-7. 



X Scripta Bot. Hort. Univ. Petropolitanfe, fasc. sxiii. (1905-6) pp. 115-21 

 Russian, pp. 122-3 German (6 figs.) See also Bot. Centralbl., civ. (1907) pp. 210-11. 

 § Journ. Linn. See. (Bot.), xxxvii. (1906) pp. 330-1 (1 pi.). 



